Centrifugal condensing apparatus

ABSTRACT

A DEVICE FOR ENABLING A LIQUID TO BE DISCHARGED FROM A ROTATING CHAMBER THROUGH AN END OPENING FORMED IN A CASING PORTION THEREOF AND FOR PREVENTING A GASEOUS FLUID FROM FLOWING THROUGH SAID OPENING IN EITHER DIRECTION, WHICH COMPRISES THE OUTER SEMITORIC HALF OF A TORIC CHANNEL WITH ONE OPENING OF THE CHANNEL DIRECTLY AND SEALINGLY CONNECTED TO SAID CASING END OPENING AND WITH THE CONVEX SURFACE OF THE CHANNEL IN A POSITION RADIALLY MORE REMOTE FROM THE ROTATIONAL AXIS OF THE CHAMBER THAN SAID OPENING, A DISC TRANSVERSE TO THE AXIS EXTENDS RADIALLY INTO THE CHAN-   NEL SO THAT, UPON LIQUID BEING DISCHARGED FROM SAID CASING END OPENING, SAID LIQUID FIRST FILLS SAID CHANNEL TO FORM A LIQUID PLUG BEFORE ISSUING AT THE OTHER END OF THE CHANNEL. IN A PREFERRED EMBODIMENT THE CASING END OPENING AND THE CHANNEL EXTEND, WIDTHWISE, CIRCUMFERENTIALLY AROUND THE ENTIRE CHAMBER.

Mardi 2, l971 Y A. JAVET CENTRIFUGAL CONDENSING APPARATUS Filed July 5, 1968 2 Sheets-Sheet l cooLANT CONDENSATE AND COOLANT COOLANT United States Patent Oiee 3 567 589 CENTRIFUGAL CONDENSING APPARATUS Alain Javet, Grange-Canal, Geneva, Switzerland, assignor to The Battelle Development Corporation, Columbus,

U.S. Cl. 202-189 10 Claims ABSTRACT OF THE DISCLOSURE A device for enabling a liquid to be discharged from a rotating chamber through an end opening formed -in a casing portion thereof and for preventing a gaseous iluid from flowing through said opening in either direction, which comprises the outer semitoric half of a toric channel with one opening of the channel directly and sealingly connected to said casing end opening and -with the convex surface of the channel in a position radially more remote from the rotational axis of the chamber than said opening, a disc transverse to the axis extends radially into the channel so that, upon liquid being discharged from said casing end opening, said liquid first ills said channel to form a liquid plug before issuing at the other end of the channel. In a preferred embodiment the casing end opening and the channel extend, widthwise, circumferentially around the entire chamber.

The present invention provides improved apparatus for condensing vaporized substances, which is designed to do away with the pumping means that are normally used for removing the resulting condensate and non condensable gaseous substances.

The apparatus provided by the present invention for condensing vaporized substances comprises a rotatable condensation chamber having an inlet for the intake of said vaporized substances and a part for the discharge of the condensed solution, means for atomizing within said chamber a liquid for cooling said products, a fluid jet extractor for clearing said chamber of non condensable gases and a fluid llow control channel which communicates with said port on the outside of said chamber and which has an outline such that its flow axis forms substantially a U of which one limb begins at the end of the channel adjacent said port and the other limb ends at the opposite, discharge, end of the channel, whereas the bottom of said U is positioned on the side opposite the axis of rotation in relation to said channel ends.

In the accompanying diagrammatic drawings:

FIG. 1 is vertical section of a first embodiment of the condensing apparatus provided by the invention;

FIG. 2 is an axial section, on an enlarged scale, of a constructional detail visible in FIG. l;

FIG. 3 is a vertical section of a second embodiment of the condensing apparatus provided by the invention; and

FIG. 4 shows in axial section and on an enlarged scale a constructional detail of FIG. 3.

The condensing apparatus shown in FIG. l is intended to be secured, for instance, to the rotary casing of a centrifugal evaporator 1 which is only partly visible, so as to be rotatably driven thereby.

It comprises a casing `2 having a frusto-conical side-wall 2a and a bottom 3 which is open at 4 to provide a passage for vaporized substances which are to be condensed and which rise up from the evaporator through a first duct section 1a, secured to the evaporator, and through a second duct section 4a which is secured to the underside of the condenser bottom 3.

Patented Mar. 2, 1971 The frusto-conical side-Wall 2a is connected to the bottom 3 by a circumferential ange 5 which, in cross-section, has the shape of a slightly opened out U formed with limbs of unequal length, and by twelve radial webs 6 of which only seven are visible.

The space lying between the flange S and the bottom 3 of the condensing apparatus forms a U-shaped channel 7 whose function will be described further on.

The condensed solution which -is produced by the apparatus flows through the channel 7 and is discharged into a stationary collecting trough 8 which has a spirally inclined bottom and which entirely surrounds ange 5, whence it may be conveyed through a drain pipe 9 to, for instance, a storage tank, not shown.

At the centre of the top wall 2b of casing 2 is formed a circular opening in which is rigidly mounted a tube 10 extending axially downwardly into the condensation chamber over the greater part of its axial length and upwardly into a rotary seal coupling 11 arranged in the orifice of a conduit 12 connected to a source, not shown, of cooling liquid.

The portion of the tube 10` which extneds into the condensation chamber is closed off at its lower end and is formed with a plurality of micro apertures 13 adapted to spray the cooling liquid into the condensation chamber in vaporized form.

The condensing apparatus is further provided with means to enable the non condensable gases to be cleared from the condensation chamber. These means include a fluid jet extractor 14 which is supplied with liquid by a hose 15 connected to tube 10 and to which is fitted a suction tube 16 extending upwardly into the uppermost region of the condensation chamber, where the gases gen erally congregate.

The fluid jet extractor 14 is positioned radially in the region of the apparatus delimited by the iiange 5 and the bottom 3 and extends into the upper limb of channel 7 and its radially outer, outlet, end projects fluid-tightly through flange 5 into collecting trough 8.

Extractor 14 is of conventional construction as is apparent from FIG. 2. It consists of a cylindrical body 17 formed with an enlarged recess 18 at its radially inner end for receiving a nozzle 19, and with an axial passage 20 communicating with recess 18` for discharging the gases sucked in through tube 16 and the liquid ejected by nozzle 19.

The above described condensing apparatus operates as follows:

When the evaporator 1 -is operating, it rotates about its vertical axis, driving therewith the condenser, and it yields a certain amount of evaporated substances which are to be condensed by the condenser.

These evaporated substances rise up through duct sections 1a and 4a into the condensation chamber and in particular into the portion thereof lying between the casing 2 and the tube 10, into which portion tube 10 sprays as described a cooling liquid, the nature of the latter being determined from case to case in dependence on the kind of substances having to be condensed. Thus, if these substances consist of solvents having well defined characteristics, such as for instance benzeneand acetone, the cooling liquid will preferably also consist of benzene or acetone.

The condensation of the vaporized substances rising up from the evaporator 1 thus takes place by the encounter and intimate contact of the cooling liquid particles with the molecules of the substances within the chamber portion lying between the tube 10 and the side wall 2a. A liquid solution consisting of a mixture of the cooling liquid and of the condensate of the vaporized substances thus comes to ow along the inner surface of side wall 2a. This soluf tion is subject to the action of centrifugal force which compels it to flow downwards along the side wall 2a, in view of its flared shape, towards the Channel 7.

When the solution reaches the edge of this channel it is forced into the latter under the action of the centrifugal force and progressively first comes to fill its rounded portion 7' then to rise radially on opposite sides of the peripheral portion of the bottom 3.

The presence of the fluid jet extractor 14 and the pressure drop caused by any form of condensation in an enclosed space cause the pressure in the condensation chamber to be very much less than the atmospheric pressure which prevails, for instance, in the collecting trough 8. Consequently the radial depth of the liquid which 'will have accumulated in channel 7 on opposite sides of disc 3 will be different as shown by the broken lines, this depth being considerably greater on the top side of disc 3 since the low static pressure which prevails in the condensation chamber will have to be compensated by a relatively substantial column of liquid subjected to centrifugal force.

Once channel 7 has filled with liquid solution and if there is no further inflow of solution, the channel remains filled and the solution contained therein forms an annular gastight plug preventing air from entering into the condensation chamber.

But if there is a further inllow of solution into the upper limb of channel 7, this additional mass of liquid, which is subjected to centrifugal force, =will exert on this limb a radial thrust, which will set the liquid plug closing oft` the channel in motion towards the outlet thereof and a corresponding amount of solution will be discharged into the collecting trough 8. This discharge will of course cease as soon as the inflow of liquid solution into the upper limb of channel 7 stops, and such inilow will clearly only be interrupted if the supply of cooling liquid into tube 10 is cut olf. The same also applies to the operation of the fluid jet extractor l14 whose nozzle 19 is directly connected to the tube 10.

The condensing apparatus shown in FIGS. 3 and 4 is more particularly intended to be mounted on a non-rotating evaporator 21, and comprises a condensation chamber 22 formed by a rotary bell-shaped casing 23 and a stationary disk-like base 24 formed at its centre 'with an opening 24 for the inflow of vaporized substances issuing from the evaporator and rising up through a first duct section 21a fixed to the evaporator and through a second duct section 24a extending downwardly from the base 24 and secured around the opening 24'.

The frusto-conical side-wall of the casing 23 is provided along its lower edge with a peripheral flange 25 which is bent so as to have, in cross-section, the shape of a slightly opened out U with limbs of unequal length and which circumferentially envelops the edge portion of the disk-like base 24.

The space which lies between the flange 25 and the disklike base 24 and which is identified as 27 is divided by twelve vertically positioned radial webs 26 into a corresponding number of radial U-shaped channels 27', whose function will be explained further on.

A stationary circular trough 28 having a spirally inclined bottom is mounted around flange 25 and co-axially therewith foi collecting the condensed solution produced by the apparatus and issuing through channels 27', a drain pipe 29 being connected to the lowermost point of the trough 28 for conveying the collected solution to a storage tank not shown.

The bell-shaped casing 23 is rigidly secured at its top to a shaft 30 rotatably mounted in two very diagrammatically represented bearings 31 and 32. The shaft 30 and hence the bell-shaped casing 23 are rotatably driven by an electric motor 36 through the intermediary of a grooved 'wheel 33 carried by shaft 30, a grooved pulley 35 carried by the motor drive shaft and a tensioned transmission belt 34 passing round wheel 33 and pulley 35.

Through a side opening in the duct section 24a extends a conduit 37 which is connected at its lower end to a source (not shown) of cooling liquid and which is bent to project vertically upwards through duct section 24a and into chamber 22, in co-axial alignment therewith and with the upper end thereof lying in close proximity to the top of the bellshaped casing 23. Above the level of channels 27 the duct 37 is formed with a plurality of apertures 38 and, as with duct 10 and apertures 13 in the previous embodiment, duct 37 and apertures 38 serve to introduce, in atomized form, the refrigerating liquid into the condensation chamber 22.

The function of the trough 28 and of the disk-like base 24 of chamber 22 is also similar to the corresponding parts in the previous embodiment even though base 24 is here stationary. Since base 24 is stationary the IWebs 26 are not secured, as in the previous embodiment, to the base 24 and a slight clearance has to be left between each web and the base to allow relative movement thereof. In the presence of these clearances, a slight amount of liquid solution will tend to pass from one radial channel 27 to another through the clearances during operation of the apparatus.

The present embodiment is also provided with a liquid jet extractor 39 for clearing non-condensable gases from the chamber 22 but as is apparent from IFIG. 3 its location is quite different from that of the extractor used in the previous embodiment. Another basic difference is that extractor 39, which rotates with the casing 23, is here required to cooperate with a stationary tube 37 instead of a rotating tube.

Referring to FIG. 4 it will be observed that tube 37 is formed at its upper end with a reduced diameter portion 37a which extends, over the greater part of its length, into a distribution chamber 40 formed on the underside of shaft 30 and rotating therewith. Fluid tightness between the tube portion 37a and the chamber 40 is ensured by a labyrinthal rotary seal device 42.

Into an opening formed in the side-wall of chamber 40 is fitted a nozzle 41 through which liquid flowing into chamber 40 from tube 37 via portion 37a is ejected through an axial passage 43 formed in the body of extractor 39, which body is secured to and extends fluidtightly through the side wall of casing 23. As shown, the nozzle 41 opens at the head of passage 43 into a recess which has a diameter greater than this passage and which communicates with chamber 22 via a lateral port 44 through which are sucked the non condensable gaseous substances within chamber 22, generally accumulating in the upper region thereof. These gaseous substances are discharged into a space lying between a hood 45, indicated in chain-dotted lines in FIG. 3, and the casing 23, this hood -being preferably fluid-tight and in communication with the trough 28.

Although in both of the illustrated embodiments the castings are shown to have frusto-conical side walls, it is clear that the casing side walls could by way of alternative, be cylindrical or have a polygonal cross-section.

It is also clear that the described condensing apparatuses could operate just as well rotating about an axis having a position other than vertical, since gravity normally plays practically no part at all on the liquids compared to the action of the centrifugal force.

Further, the webs which are mounted in the circumferential folded-over flanges could extend along nonradial planes so chosen as to facilitate the llow of the liquid solution, for instance along a spiral course, so as keep highly homogeneous the liquid fluidtightness plug which the solution is required to form at all times in the U- shaped channel between the flange and the disk-like base of the condensing apparatus.

What is claimed is:

1. Apparatus for condensing vaporized substances comprising:

(a) a rotatably mounted enclosed chamber formed with an intake for receiving vapors and an annular exit port that extends circumferentially around the vertical axis of rotation of said chamber so that,

upon rotation of said chamber, liquids are centrifugally urged through said port;

(b) means for rotating said chamber;

(c) means for spraying a cooling liquid within said chamber so that condensable vapors therein may be cooled to condense and flow to said exit port;

(d) means for removing uncondensable gases or vapors from said chamber;

(e) a liquid flow channel comprising the outer portions of a torus extending around said chamber directly and sealingly connected at one end to said exit port, a disc extending transversely to the rotational axis into the channel, the channel liquid flow axis being semitoric in shape extending from said port outwardly and then turning inwardly around the disc periphery, said channel being open at its outflow end to the atmosphere exterior to said chamber so that liquid, ltlowing through said exit port will collect within said semitoric channel to a limited extent due to the difference between the pressure of said atmosphere and the lower pressure within said chamber caused by condensation of said vapors therein and by the removal of said uncondensable gases, thus sealing said exit port from said atmosphere but permitting liquid 110W through said channel when the effect of the centrifugal force overcomes said pressure difference.

2. Apparatus as set forth in claim 1, wherein said means for removing uncondensable gases or vapors consists of a uid jet extractor that is supplied with liquid by said cooling liquid spraying means.

3. Apparatus as set forth in claim 1, wherein said chamber is cylindrical in shape.

4. Apparatus as set forth in claim 1, wherein said chamber is bellshaped having side walls that flare outwardly from said axis of rotation to said circumferential exit port.

5. Apparatus as claimed in claim 4 wherein said spraying means are fixed to the top of said bell-shaped chamber and extend into said chamber over at least a portion of its axial length, and wherein the fluid jet extractor having a jet nozzle therein is positioned radially in the volume delimited lby said annular chamber through which its ejecting end projects, a conduit connecting the jet nozzle of said extractor to said spraying means and a tube rising from the ejection passage to the upper portion of said chamber to draw away non condensable gases that have accumulated in said portion.

6. Apparatus as claimed in claim 4 wherein said spraying means is independent of said bell-shaped chamber, is stationary and extends axially into said bell-shaped chamber to near the top thereof, and wherein said spraying means is provided at its upper end with a reduced diameter portion projecting into a distribution chamber rigid with the top of said chamber to rotate therewith, a noncondensable gas-vapor extractor having a jet nozzle therein, said distribution chamber feeding cooling liquid to the jet nozzle of said extractor, the axial passage of said extractor being positioned radially near the top of said casing through being secured in a sealed through passage formed in the side wall of said chamber coaxially with said nozzle.

7. Apparatus as set forth in claim 1 wherein said disc is formed as an end closure plate that is spaced from the exit port of the chamber, said circumferential exit port constituting the space between said closure plate and the sidewall of said chamber, the radius of said plate from said axis [being greater than the maximum distance of said sidewall from said axis so that said plate extends beyond said sidewall, said liquid ow channel being formed by an annular wall extending laterally outwardly from said sidewall and curving inwardly around the end of said plate While being spaced therefrom leaving a semitoric space therebetween.

8. Apparatus as claimed in claim 7, wherein said plate forms the bottom of said chamber and is adapted to rotate with said chamber.

9. Apparatus as claimed in claim 7, wherein said plate forms the bottom of said chamber and is stationary.

10. Apparatus as claimed in claim 7, wherein an annular collecting trough having a semitoric bottom surrounds at least the annular outlet opening of the channel.

References Cited WlLBUR L. BASCOMB, JR., Primary Examiner J. SOFER, Assistant Examiner Us. C1. XR. 

